The EffectLiteR Approach for Analyzing Average and Conditional Effects

We present a framework for estimating average and conditional effects of a discrete treatment variable on a continuous outcome variable, conditioning on categorical and continuous covariates. Using the new approach, termed the EffectLiteR approach, researchers can consider conditional treatment effects given values of all covariates in the analysis and various aggregates of these conditional treatment effects such as average effects, effects on the treated, or aggregated conditional effects given values of a subset of covariates. Building on structural equation modeling, key advantages of the new approach are (1) It allows for latent covariates and outcome variables; (2) it permits (higher order) interactions between the treatment variable and categorical and (latent) continuous covariates; and (3) covariates can be treated as stochastic or fixed. The approach is illustrated by an example, and open source software EffectLiteR is provided, which makes a detailed analysis of effects conveniently accessible for applied researchers.     

SIMSTAT: Bootstrap computer simulation and statistical program for IBM personal computers

SIMSTAT is a computer program that provides bootstrap confidence intervals and estimates distribution parameters for 27 univariate and bivariate statistics. Because it permits variation of the bootstrap sample size, it is a convenient tool for research planning, allowing comparison of power estimates and estimator precision for various estimators and/or sample sizes. SIMSTAT also is a useful tool for studying the robustness of various statistics on real-world data and may be helpful in teaching statistical principles.     

Linguistic and other psychological aspects of paroxysmal aphasia

A case of paroxysmal aphasia is reported. Aphasic spells occurred, in this patient, without modification in consciousness and without involvement of behaviors others than those related to oral and written speech and language. Longer spells successively recapitulated the clinical pictures of global, Wernicke's, conduction, and amnestic aphasia. Besides aphasiological evaluations, neurological, psychometrical, electroencephalographical, and CT-scan documents were obtained. The discussion bears on four main points: the linguistic characteristics of paroxysmal aphasia as compared to those of aphasias of other etiologies; Pierre Marie's oneness doctrine of aphasia; the mutual relationships of language and thought (in aphasia); the affective experience lived by one with severe aphasia, with special reference to the notion of anosognosia.     

Locus of the redundant-signals effect in bimodal divided attention: A neurophysiological analysis

We reanalyzed the data from the study of Lamarre, Busby, and Spidalieri (1983). In that study, the activity of single neurons in area 4 of the motor cortex was recorded during a bimodal detection task in which a monkey (Macaca mulatta)had to respond as quickly as possible to a visual or an auditory signal or to both (redundant trials). Manual responses on redundant trials were speeded by the presence of both signals, as is typically found. The times between signal onsets and the first changes in neuronal activity were also speeded by redundant signals, but there was no difference between redundant-signals and single-signal trials in the time between the change in neuronal activity and movement onset. These results suggest that late motor processes are not speeded by redundant signals in bimodal detection tasks.     

Maternal odor shapes rapid face categorization in the infant brain

To successfully interact with a rich and ambiguous visual environment, the human brain learns to differentiate visual stimuli and to produce the same response to subsets of these stimuli despite their physical difference. Although this visual categorization function is traditionally investigated from a unisensory perspective, its early development is inherently constrained by multisensory inputs. In particular, an early‐maturing sensory system such as olfaction is ideally suited to support the immature visual system in infancy by providing stability and familiarity to a rapidly changing visual environment. Here, we test the hypothesis that rapid visual categorization of salient visual signals for the young infant brain, human faces, is shaped by another highly relevant human‐related input from the olfactory system, the mother's body odor. We observe that a right‐hemispheric neural signature of single‐glance face categorization from natural images is significantly enhanced in the maternal versus a control odor context in individual 4‐month‐old infant brains. A lack of difference between odor conditions for the common brain response elicited by both face and non‐face images rules out a mere enhancement of arousal or visual attention in the maternal odor context. These observations show that face‐selective neural activity in infancy is mediated by the presence of a (maternal) body odor, providing strong support for multisensory inputs driving category acquisition in the developing human brain and having important implications for our understanding of human perceptual development.     

What is matched in direct matching? Intention attribution modulates motor priming

Converging evidence has shown that action observation and execution are tightly linked. The observation of an action directly activates an equivalent internal motor representation in the observer (direct matching). However, whether direct matching is primarily driven by basic perceptual features of the observed movement or is influenced by more abstract interpretative processes is an open question. A series of behavioral experiments tested whether direct matching, as measured by motor priming, can be modulated by inferred action goals and attributed intentions. Experiment 1 tested whether observing an unsuccessful attempt to execute an action is sufficient to produce a motor-priming effect. Experiment 2 tested alternative perceptual explanations for the observed findings. Experiment 3 investigated whether the attribution of intention modulates motor priming by comparing motor-priming effects during observation of intended and unintended movements. Experiment 4 tested whether participants' interpretation of the movement as triggered by an external source or the actor's intention modulates the motor-priming effect by a pure instructional manipulation. Our findings support a model in which direct matching can be top-down modulated by the observer's interpretation of the observed movement as intended or not.     

The factor structure of the Beck Depression Inventory-II: an evaluation

The Beck Depression Inventory-II (BDI-II) is a frequently used scale for measuring depressive severity. BDI-II data (404 clinical; 695 nonclinical adults) were analyzed by means of confirmatory factor analysis to test whether the factor structure model with a somatic-affective and cognitive component of depression, formulated by Beck and colleagues, has a good fit. We also evaluated 10 alternative models. The fit of Beck's model was not good for all criteria. Three of the alternative models had a better fit in both samples, but none of these met all criteria for good fit. Of the alternatives with a better fit, we selected the only model with unidimensional subscales, which assesses a somatic, affective, and cognitive dimension. For this model, which we recommend, as well as for Beck' original model, a good fitting structure containing 15 and 16 items was developed with an item-deletion algorithm.     

Brazilian version of the Protocole Montréal d'Evaluation de la Communication (Protocole MEC): normative and reliability data

The lack of standardized instruments to evaluate communication disorders related to the right hemisphere was verified. A new evaluation tool was developed: Protocole Montréal d'Evaluation de la Communication--Protocole MEC, adapted to Brazilian Portuguese--Bateria Montreal de Avalia??o da Comunica??o--Bateria MAC (Montreal Evaluation of Communication Battery). The purpose was to present stratified normative data by age and educational level, and to verify the reliability parameters of the MEC Battery. 300 individuals, between the ages of 19 and 75 years, and levels of formal education between 2 and 35 years, participated in this study. They were divided equally into six normative groups, according to three age categories (young adults, intermediary age, and seniors) and two educational levels (low and high). Two procedures were used to check reliability: Cronbach alpha and reliability between evaluators, Results were established at the 10th percentile, and an alert point per task for each normative group. Cronbach's alpha was, in general, between .70 and .90 and the average rate of agreement between evaluators varied from .62 to .94. Standards of age and education were established. The reliability of this instrument was verified. The psychometric legitimization of the MEC Battery will contribute to the diagnostic process for communicative disorders.